1. Field of the Invention
The invention relates to a representative image display method and apparatus comprising of a series of multiple images into which a motion image is formed, and which displays a representative image of each scene, and to motion image search apparatus which execute searches for a motion image using the representative image display apparatus.
2. Description of Prior Art
Generally, a motion image contains multiple scenes. Each scene has independent meaning, and is defined by a group of consecutive images. FIG. 2 shows a situation where three scenes have been recorded on a video tape. Scene A is a view of a person, scene B is of a house, and scene C is of an automobile. Each scene respectively comprises two (A1 and A2), two (B1 and B2). and three (C1-C3) images. A motion image search apparatus is used to quickly select a required scene from a motion image on recorded media, such as video tapes, when editing motion images such as those required in a multimedia presentation creation or in broadcasting. Recently, apparatus have been developed that display a representative image (hereinafter referred to as representative image) of each scene after a motion image has been partitioned into scene units, and that allow a desired scene to be selected using the representative image as an index.
FIG. 3 is a block diagram from a catalog for "Mediachef/CUT" by Hitachi, Ltd. showing a system using the product. Details of its operation are given in "Mediachef/CUT for Windows User Operation Manual" (Windows is a registered trademark).
In the figure, the system comprises a PC 2 which performs general control, a video playback apparatus 4 which provides the motion image to the PC 2, and a color printer 6 which prints the edited images. The PC 2 contains a video capture board 8 which captures and digitizes images provided from a video playback apparatus 4. This configuration performs, for example, the following steps.
(1) First the motion image to be processed is loaded, (2) a transition point in the scene is automatically identified based on the degree of color change in the images, (3) an image is decided to be a representative image that appears immediately after the transition point is observed, and (4) the representative image is stored or printed as an index for each scene. In the case of FIG. 2, a scene transition point is identified between A2 and B1, and between B2 and C1, and the leading images of each scene, B1 and C1, become the representative images.
This system helps the user in tape editing, for example, by printing out the representative images contained in one video tape cassette in a small sheet and affixing the sheet to the side of the video tape cassette. In addition, editing processes such as sorting, deletion, and trimming of the scenes are possible on the PC 2.
In the system described above, referencing the representative images allows the user to look for desired scenes and replay them, that is, to search for a motion image. However, in representative images where a ship is afloat on the ocean, for example, the direction of the ship's movement can only be determined by replaying the motion image. If several representative images of this sort exist, for example, when searching for pictures where the ship moves to the right, the user must check each scene containing the representative image one by one. This manual search is not only laborious when there are a large number of similar representative images, but inconvenient when one tries to grasp the general movement of a motion image, and leaves much room for improvement for efficient editing.